The invention relates to a brake disc pot for a disc brake of a motor vehicle.
A conventional wheel and its bearing is constructed of the wheel bearing component, the wheel hub component having a wheel mounting flange and a rim component with the tire. The rim is fastened to the wheel mounting flange by means of tire bolts. The brake disc is clamped between the rim and the wheel mounting flange by way of a brake disc pot. Such a wheel bearing arrangement is described in German Patent document DE 101 32 429 A1. The maximal brake disc friction radius is determined here by the chain of measurements of internal rim radius minus height of the caliper bridge minus half the lining height. In the case of high-powered vehicles, it is therefore often necessary to use a larger rim in order to accommodate the required brake disc size.
Furthermore, composite brake discs are known, with a friction ring made of gray cast iron, connected with a brake disc pot made of light metal. German Patent document DE 100 24 819 A1 describes, among others, so-called built-up brakes discs, where the friction ring and the pot are joined by means of separate elements, such as pins, screws, etc. In this case, the brake disc pot has a bottom and a surrounding wall and is made of an aluminum alloy.
A wheel with a double brake disc and its bearing are constructed of the wheel bearing component, the wheel hub component with the wheel mounting flange and of a rim component with the tire. The rim is fastened to the wheel mounting flange by means of wheel bolts, in which case the double brake disc is clamped by way of a brake disc pot between the rim and the wheel mounting flange. A wheel bearing arrangement of this type is described in German Patent document DE 10 2006 052 177 A1.
A further double brake disc is described in German Published Patent Application DE 1 800 549. There, the brake discs are connected directly with the wheel hub, and only a slightly ventilated area is created between the two brake discs, which is not beneficial to the cooling of the brake discs, for example, during a sustained braking.
German Utility Model G 87 02 630.9 describes a construction of a double brake disc provided with cooling, apparently for a wheel assembly with a double disc brake for rail vehicles. As shown in G 87 02 630.9, each brake disc is connected in one piece by way of arms 21 parallel to the axis with a fastening ring 19, which is held in a centered manner on the axle shaft by a supporting ring 13. Air can flow through between the arms 21 into the space between the brake discs. In this case, the brake disc has a very complicated construction and its manufacturing is very costly. In addition, the construction is less suitable for a motor vehicle.
It is an object of the present invention to provide wheel assemblies having single-disc brakes or double-disc brakes for a vehicle, which have a brake disc pot that has a weight-saving design, assists the cooling of the brake disc and furthermore avoids the above-mentioned disadvantages.
According to the invention, this and other objects are achieved by a brake disc pot for a disc brake having a device for the centered attachment of at least one brake disc and having a device for guiding cooling air in the radial direction toward the brake disc. The brake disc pot has recesses on its periphery.
According to the invention, a brake disc pot for a disc brake having a device for the centered attachment of at least one brake disc and having a device for guiding cooling air in the radial direction toward the brake disc, particularly into the space between two brake discs, is characterized in that the brake disc pot has recesses on its periphery.
A brake disc pot designed as a “framework” has the advantage that cooling air can flow in the radial direction out of the brake disc pot along the brake disc, which contributes to an effective cooling of the brake disc and of the caliper. In addition, the brake disc pot can be designed in this manner to be light and in filigree, which has significant weight-related advantages without having to accept cutbacks with respect to structural strength. If the brake disc pot has a device for the centered parallel-spaced attachment of two brake discs, air flowing through the space between the two brake discs will meet hardly any resistance but rather will be beneficial, which contributes to an excellent cooling of the brake discs and of the caliper.
In an advantageous embodiment of the invention, the brake disc pot is characterized in that, viewed from the brake disc, this brake disc pot extends essentially in one direction. In this case, the framework ribs or webs may extend perpendicular to the inside diameter of the brake disc pot or may be slightly skewed.
In the case of an embodiment with two brake discs spaced parallel, the brake disc pot extends essentially between the two brake discs.
In a further embodiment, the brake disc, by way of, in particular, six to ten centering and/or attaching projections, is fixed to the brake disc pot by means of attaching devices extending in the axial direction, particularly screws and/or rivets. The centering and/or attaching projections are oriented toward the interior from an inner diameter of the brake disc. The brake disc is guided in the axial direction, on the face, from one side, to the brake disc pot and, placed on centering shoulders of the brake disc pot. If the brake disc and the brake disc pot are parts which can be separated from one another, the manufacturing of each part will be simple and reasonably priced. In addition, an exchange of the brake discs can be carried out without having to remove the entire wheel assembly. In this case, it is an advantage for the brake disc pot to center the brake disc in the radial and axial direction. If the connection is relocated in the direction of the friction rings, instead of being arranged on the outer diameter of the brake disc pot in the axial direction, even more weight can be saved.
In a further preferred embodiment of the invention, the brake disc pot has a frame which forms its periphery and its recesses and consists of an essentially V-shaped, in particular, meandering profile of the same or of a different cross-section. In the case of the double brake disc, the profile may extend essentially in a V-shape from one brake disc to the next. In both cases, a brake disc pot can be designed that constructively is particularly light, with a simultaneously advantageous diffusion of stress in the profile of the frame. This is so, especially if the frame profile, particularly a frame profile of a meandering shape, extends from one brake disc to the next. Furthermore, as a result of the construction, vibrations in opposite directions between the friction rings of the brake discs can be absorbed and compensated. In general, the thermal axial distortion—the shielding—is reduced in that the friction ring is connected in a finger-type manner by way of attaching projections, and the brake disc pot can thereby absorb deformations in the friction ring and can yield to them. A reasonable priced manufacturing is also made possible, for example, by die casting without undercuts in the mold.
The frame profile can advantageously be reinforced by a pot plate which extends in the radial direction. In this case, the frame profile and/or the pot plate may then consist of a light metal alloy and both can advantageously be cast in one operation. The weight is thereby enormously reduced in comparison to gray cast iron material and, in addition, as a result of the lightweight construction of the pot in comparison to the solid-bowl pot. For a design that meets the stress requirements, the transition areas from the frame to the pot plate may be reinforced at least partially by an accumulation of material.
The brake disc mounting is especially facilitated by an embodiment of the invention in which, in the case of the brake disc, on one side, the brake disc centering device and/or the brake disc attaching device and, on the other side, the pot plate is constructed at the frame profile situated on the outside in the axial direction, particularly at the points of the V-base, at the exterior side. In the case of a double disc, the brake disc centering device and/or the brake disc attaching device is constructed at the frame profile situated on the outside in the axial direction, particularly at the points of the V-base, on the exterior side.
While a further advantageous embodiment is characterized in that the ribs of the frame have a cross-sectional profile in the area of the recesses, which is suitable for conveying air, by means of its rotation, from the brake disc pot in the radial direction to the outside through the recesses along the brake disc, into the brake disc, or between the brake discs, the brake disc or brake discs are actively supplied with air for cooling purposes, which cools these brake discs particularly when slowly driving downhill.
The design has a particularly advantageous effect on the conveying of air if the ribs of the frame in the area of the recesses have a cross-sectional profile which has an acute angle, whose vertex, viewed in the rotating direction of the brake disc pot, because of the radiuses used at the cross-sectional corners, is situated in front of the cross-sectional profile, particularly on a tangent at the inside diameter of the brake disc top, and its legs, viewed from the vertex, extend in the direction away from the rotating direction of the brake disc pot. If the cross-sectional profile of the ribs corresponds essentially to a parallelogram, with a vertex of its lower acute corner angle situated in front in the rotating direction of the brake disc pot, particularly essentially on the inner diameter of the brake disc pot, the design is easy to implement with respect to casting. For this purpose, it is also necessary that the ribs of the frame have a cross-sectional profile in the area of the recesses, which cross-sectional profile has rounded edges, particularly constructed as cast radiuses.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.